Method of making refractory brick



1953 J. M. FRANK ETAL 3,100,677

METHOD OF MAKING REFRACTORY BRICK Filed July 24, 19 59 2 Sheets-Sheet 1/2 27% K MW 1953 J. M. FlANK EI'AL 3,100,677

METHOD OF MAKING REFRACTORY BRICK Filed July 24, 1959 2 Sheets-Sheet 2FIG,I4

United States Patent 3,10%,677 METHOD 0F MAKING REFRACTORY BRICK JosephM. Frank, Neil E. Boyer, and James A. Crookston,

Mexico, Mo., assiguors to A. P. Green Fire Brick Company, Mexico, Mo., acorporation of Missouri Filed July 24, 1959, Ser. No. 829,342 5 Claims.(Cl. 18-59) The present invention relates to a novel method for metalencasing refractory brick for use in the construction of various partsof furnaces, and to a novel metal cased refractory brick made by saidmethod. The brick are widely used in metallurgical furnaces, and, inparticular, in the basic open-hearth furnace used for making steel.ThQbIlCk usually is encased on four sides with the ends uncased,however, less than four sides may be cased and the ends also may becased.

The purpose of the external plates on the brick is primarily to providea bonding medium between adjoining brick, which tends to make thefurnace structure more resistant to the effect of thermal shock and theattacks of slags and furnace fumes in service. The metal plates tend tooxidize and melt in service, fusing adjoining brick into a more or lessmonolithic structure on the surface facing the interior of the furnace.At the same time the metal plate further back into the furnace wallretains its integrity, thus providing support to the furnace wall duringthe life of the furnace structure. The brick without external plates aremore subject to thermal shock and to sheeting due to changes instructure resulting from attack by slags and fumes than are brick withexternal plates.

There are numerous methods used to apply these casings to refractorybrick. One method is to press the brick mix into a channel previouslyinserted into the press cavity, thus forming a metal case on three sidesof the brick. The fourth side can then be left free of a metal casing,or a metal casing can be applied through pressure from the upper plungerof the press. In this latter case, the applied metal plate hasprojections which anchor it to the brick. Another method which is used,is to attach the metal plates toany or all sides of the brick by meansof adhesives. Another method is to use a channel of the proper size andto force the channel apart, insert the previously formed brick into thechannel, and then to allow the channel to assume its normal position sothat it is held to the brick by its spring. This method may be used inconjunction with adhesives.

Another recent method of preparing cased brick is to form a refractorybrick in a normal manner and then place two U-shaped channels over thebrick from opposite faces in a manner that the legs of the channelsoverlap. The overlapping legs are then spot welded together to form abrick with a double thickness of metal on each side. 1

In addition to the external plates described above, it is also commonpractice toplace one or two plates inside the brick. The purpose of thisis to provide the brick with even more resistance to the effects ofthermal shock and breaking-off or sheeting of the brick in service dueto attack by furnace fumes and slags. The internal plates are placedinside the brick in such manner that their long dimensions areperpendicular to the hot-face of the brick as it occurs in service.Thus, the internal plates effectively divide each brick into two orthree smaller brick separated by metal plates. By means of theseinternal plates, the brick are made more resistant to the destructiveprocesses which occur in service than brick having only external plates.p

The principal method used to place the internal plates in the brick isan adaptation of the method hereinbefore 3 ,l00-,677 Patented Aug. 13,1963 described for forming the brick into a channel previously insertedinto the press cavity. In this instance, a second channel of smallercross-section but the same length and approximately the same height isplaced inside the channel forming the outside casing for the brick. Thebrick is then pressed, simultaneously forming both the outside metalcasing on three sides and the two internal plates. To form a singleinternal plate, a T-shaped metal form is used in place of the smallerchannel. The fourth side can be externally plated as described. Anothermethod which is used to provide the internal plates is to press smallerbrick and combine two or three of them into a composite with separatingplates to form a full-size brick with both internal and external plates.Another method is to saw a full-size brick into two or three smallerbrick and combine these into a composite brick with separating plates toform a full-size brick with internal and external plates. Another recentmethod is to prefabricate a box of the same external dimensions as thebrick which is to be formed. This box is made up of the two side membersand the end members but with no top and bottom members. Inside the boxone or two plates: of similar size to the side members are fastened soas to divide the width of the box into two or three equal parts.Theprefabricated metal box thus described is then placed into the presscavity with the open top and bottom placed so that the action of thepress will cause the brick mix to be compacted into the box. Thus onpressing, a brick is formed having metal plates on the ends and sidesand with one or two internal plates inside the brick. External platesmay then be fastened to the remainingtwo free faces of the brick bymeans of adhesives or by welding to the other metal faces.

It is an object of the present invention to provide a novel method forforming a refractory brick having its four sides encased with anintegral sheet of metal and with the ends uncased.

A further object is to provide a novel method of forming a metal casedrefractory brick which includes the steps of inserting the refractorymix in a container and forming the container into a brick of the sameperimeter :as the container but having less volume, thereby compressingthe refractory mix. Another object is to provide a cased refractorybrick having a continuous meta casing. 1

Still another object of the present inventionis to provide a method offorming a metal cased refractory brick, having internal plates. Anotherobject is to provide a casedrefractory brick having internal plates anda continuous metal casing.

These and other objects and advantages will become apparent hereinafter.

The present invention comprises a process of making cased refractoriesincluding the steps of placing a refractory mix into a hollowgeometrical shape and formingthat shape into the desired refractorybrick. The invention further consists in the process hereinafterdescribed and claimed and in the refractory brick made by said process.

H6. 1 is a perspective view of a sheet before it is formed into thecasing for a fire brick,

FIG. 2 is a perspective view of a hollow geometric shape formed in thebrick making process, 3

FIG. 3 is a perspective view of the shape shown in FIG. 2 filled withbrick mix and diagrammatically showing a vibratory motion imparted tothe filled shape,

FIG. 4 is a perspective view of the shape shownin FIG. 3 with adiagrammatic representation of a brick forming press,

FIG. 5 is a perspective view of a finished brick,

. 3 7 FIG. 6 is a perspective view of a modification of the hollowgeometric shape shown in FIG. 2,

FIG. 7 is an end view of a geometric shape containing a spacer,

FIG. 8 is an end view of the brick formed from the shape shown in FIG.7,

FIG. 9 is an end view of a geometric shape having a p modified form ofspacer contained therein,

.FIG. 10 is an end view of the brick formed from the shape shown in FIG.9,

FIG. 11 is a perspective View of a brick made of a modified form ofcasing containing perforations in the outer walls, 1

FIG. 12 is a partially broken perspective view of a modified spacerplate having perforated flanges,

FIG. 13 is an end view of a geometric shape having another modified formof spacer contained therein,

FIG. 14 is an end view of the brick formed from the shape shown in FIG.13, and

FIG. 15 is a perspective view of the brick shown in FIG. 14.

A flat sheet or metal plate 19 which preferably is carbon steel or asimilar oxidizable metal and is of any predetermined length and width(FIG. 1) is conventionally rolled and the opposite edges joined into ahollow geometric shape 11 (FIG. 2) which has an infinite number ofpossible dimensions for length, width and height. The

hollow. geometric shape is formed into the predetermined cross-sectionof established-perimeter and shape by usual sheet-metal formingtechniques and joined to form a continuous cross-section. Thecross-section of the hollow shape is shown as circular in FIG. 2 andelliptical in FIG. 6 and can be any suitable cross-section having aperimeter substantially equal to the perimeter of the refractory'brick.'The important consideration is that the perimeter of thecross-sectionof the shape be substan-v tially equal to the perimeter ofthe cross-section of the shape to which it will be transformed in thebrick-forming operation. The metal case may stretch slightly in thebrick-forming process if a sufiicient amount of refractory mix is placedin the geometrical shape before it is formed into a brick. However, theperimeter of the final brick is substantially the same as the perimeterof the hollow geometrical shape in all cases. In addition, it is anessential feature of the present invention that the area of thecross-section of the hollow geometric shape be greater than the area ofthe cross-section of the shape to which it will be transformed in thebrick-forming operation. This allows rigid control over the density ofthe final brick. The end joint of the metal sheet 11) can be overlappedas shown in FIG. 2 to form a seam 11a, or it can be butt welded, ifdesired.

Following the fabrication of the hollow geometric shape 11 from themetal sheet 10 (FIG. 2), it is filled (FIG. 3) with 'a predeterminedamount of a refractory brick mix 12. The refractory can be any knownrefractory, but is preferably a basic refractory. The amount of brickmix to be placed into the shape may be measured by weight or by volumewith similar final results. [[n addition to'merely filling the shapewith brick mix it is necessary to' compact it by means of vibration,

case 15 having sides 16 and free ends 17. The ends 17 can be left openor can have metal caps or plates attached thereto as by welding orgluing. Since the perimeter of the cross-section of the originalgeometric shape 11 is substantially equal to the perimeter of thecross-section of the final brick 14, and the area of the cross-sectionof the original geometric shape 11 is greater than the area of thecross-section of the final brick 14, a brick '14 is formed of therequired volume and density with a continuous metal casing :15 on foursides 16. The refractory part 12 of the brick 14 has a greater densitysince the cross-sectional area and consequently the volume of the metalcasing 15 is reduced in the brick-forming process. The metal case 15retains the refractory portion 12 of the brick .14by the stresses set upin the brick-forming process, and cannot be removed without thedestruction of the brick.

The process may be modified to allow the incorporation of internal steelplates 29' in the final brick'14 (FIGS. 710). The plates 20 areintroduced into the hollow geometric shape '11 prior to filling it withbrick mix 12. The shape of the internal plates 20 can vary, twopossibilities being illustrated in FIG. 7 and FIG. 9. As can be seen,FIG. 7 shows the internal plates 2t? formed in the shape of a cross,while FIG. 9 illustrates the use of plates 24 in the-form of an X. Otherpossible designs include the use of a concentric circle in the originalhollow geometric shape, which on final transformation in the pressingoperation becomes a small rectangle within a larger rectangle. Anotherpossibility is shown in FIGS. 1315 and comprises a corrugated or Sshaped plate 30 positioned in the hollow geometric shape 31 so that thefinal brick forming pressure will act to reduce the distance betweencorrugations and increase the height of the corrugations. Any design maybe used for the internal plates, so long as the plates when introducedinto the hollow geometric shape are not longer or wider than thecorresponding final brick dimensions. emples, it is apparent that manydesigns not specifically mentioned in this description could be usedwhich would not, however, depart from the spirit and scope of thisinvention. V

A modification of this invention shown in FIG. 11 is to use steel platewhich is perforated rather than solid to form the hollow geometricshapes. This produces a brick 14 including a refractory portion 12 (andla metal casing 15 having sides 16 with perforations 21 providedtherein.

Expanded metal can also be used to form the outer metal casing for thebrick, and the term perforated is intended to include such casingconstructions.

FIG. 12 shows a modified spacer plate 25 provided with perforations 26in the flange portions 27. This spacer plate also may be made fromexpanded metal. Either the solid or perforated form of the spacer can beused with all types of casings and refractory mixes.

By the use of perforated sheet steel or expanded metal as the casing andfor the internal plates, a reduction in pressure, or' a combination ofthese two mechanisms.

' to allow the assembly to be handled with a minimum of loss of brickmix.

The hollow geometric shape v111 which has been filled and compacted withbrick mix 12 is then introduced to a brick-forming press(diagrammatically indicated by the arrows 13 in FIG. 4), where theoriginal geometric shape 11 is transformed into the'final brick form 14(FIG. 5). The brick 114 includes a refractory portion 12 and a metalweight ofthe final brick is elfected while atthe same 5 time providingthe same support to the furnace structure as is provided withnon-perforated sheet steel. In addition, if the internal plates haveperforations in them,

the density of the refractory mix will be more uniform,

since it can fiow through the openingsin the plates from one compartmentto another. 7 The use of non-solid oasings and internal plates resultsin more brick units being available per ton of refractory than .if solidcasingstand plates are used.

'Ilhusit is seen that the present invention provides a refractory brickand a method of preparing same which achieves all of the objects andadvantages sought therefor. The present invention further provides abrick having an integral or continuous metal casing on four sidesthereof, said casing being formed around the brick during the brickmaking process so that it becomes in effect an From these exintegralpart with the brick, tightly adhering, and resisting any attempt atremoval without destruction of the metal case.

By reducing the volume of a given geometric shape without substantiallychanging the perimeter of the crosssection from that of the originalshape, it is possible to control the density of the final brick withinclose limits, and to achieve a very high density in the brick.

The design of the internal plates in the brick can be varied, and theinternal plates also are an integral part of the brick.

As indicated, the metal casings and spacers are usually made of lowcarbon steel, although they can be any ordinary metal or alloy,preferably one which is oxidizable at the temperature encountered in theinstallation. Stainless steel can also be used.

The brick mix used is preferably a basic refractory type such as deadburned magnesite or chrome ore or mixtures of chrome ore and magnesia.Any suitable basic refractory mix may be used.

A binder should be utilized in the brick mix to enable the brick to holdtogether without kihi firing. Binders such as dextrin, gum ara'bic,sulphite pitch, magnesium sulphate, magnesium chloride, sodiumdichroma-te, sodium silicate, etc. are suitable in amounts up to aboutby weight of the brick A further variation of this invention is to use ahollow geometric shape, the perimeter of whose cross-section is onlyslightly smaller than the perimeter of the cross-section of the finalbrick form or shape. If a sufiicient amount of refractory mix isretained in the hollow geometric shape, the final brick-formingoperation will act to stretch the met-a1 slightly, resulting in theplacement of a residual tensile stress in the metal after the brick isformed, thus providing a more tightly adhering metal case. The perimeterof the final brick is still substantially the same as the perimeter ofthe hollow geometric shape. The cross-sectional area and the volume ofthe brick are still reduced from that of the original geometric shape.

This invention is intended to cover all changes and modifications of theexamples of the invention herein chosen for purposes of the disclosure,which do not constitute departures from the spirit and scope of theinvention.

What is claimed is:

1. A method of making a metal cased refractory brick adapted to resistthe destructive effects of heat consisting of the steps of forming atubular geometrical shape having a single longitudinal seam, open ends,continuous sides and an established perimeter from a flat sheet ofoxidizable metal, temporarily closing one end of the tubular shape toeffectively prevent loss of refractory material during the subsequentfilling operation, filling the tubular geometrical shape with a basicrefractory mix through an open end thereof, vibrating said metal shapealong its length to partially compact the refractory mix within theshape to a sufficient extent to cause it to be self-supporting therein,placing the filled tube into a mold housing side and end walls of thefinal desired form and in a single compression step applying pressure tothe outer surface of said metal shape along its length in a directionperpendicular to the direction of vibration and forming the refractoryfilled geometrical shape into a metal cased refractory brick having onlyone fabrication scam in the casing and having uncased ends, said brickbeing of susbtantially the same perimeter as and of a smallercross-sectional area and smaller volume than the original geometricshape, said refractory brick having uncased ends and a tightly packedbody with a. smooth continuous metal casing integrally associatedtherewith.

2. A method of making a metal cased refractory brick adapted to resistthe destructive effects of heat consisting of the steps of forming atubular geometrical shape having a single longitudinal seam, open ends,continuous sides and an established perimeter from a flat sheet ofoxidizable metal, placing a spacer plate within the tubular geometricalshape through an open end thereof, temporarily closing one end of thetubular shape to effectively prevent loss of refractory material duringthe subsequent filling operation, filling the tubular geometrical shapewith a basic refractory mix through an open end thereof, vibrating saidmetal shape along its length to partially compact the refractory miXWithin the shape to a sufficient extent to cause it to beself-supporting therein, placing the filled tube into a mold housingside and end walls of the final desired form and in a single compressionstep applying pressure to the outer surface of said metal shape alongits length in a direction perpendicular to the direction of vibrationand forming the refractory filled geometriacl shape into a metal casedrefractory brick having only one fabrication scam in the casing andhaving uncased ends, said brick being of substantially the sameperimeter as and of a smaller cross-sectional area and smaller volumethan the original geometric shape, said refractory brick having uncasedends and a tightly packed body with a smooth continuous metal casingintegrally associated therewith.

3. The method defined in claim 2 wherein said spacer has a shape.

4. The method defined in claim 2 wherein said spacer has an X shape.

5. The method defined in claim 2 wherein said spacer is corrugated andhas an S shape.

References Cited in the file of this patent UNITED STATES PATENTS1,406,542 Crocker 'Feb. 14, 1922 1,571,087 Jackson Mar. 18, 19301,760,861 Parker May 27, 1930 1,846,290 Walter Feb. 23, 1932 2,216,813Goldschmidt Oct. 8, 1940 2,247,376 Heuer July 1, 1941 2,622,314 BerganDec. 23, 1952 2,673,373 Heuer Mar. 30, 1954 2,747,231 Reinhardt May 29,1956 2,759,256 Bergan Aug. 21, 1956 2,791,116 Heuer May 7, 1957

1. A METHOD OF MAKING A METAL CASED REFRACTORY BRICK ADAPTED TO RESISTTHE DESTRUCTIVE EFFECTS OF HEAT CONSISTING OF THE STEPS OF FORMING ATUBULAR GEOMETRICAL SHAPE HAVING A SINGLE LONGITUDINAL SEAM, OPEN ENDS,CONTINUOUS SIDES AND AN ESTABLISHED PERMETER FROM A FLAT SHEET OFOXIDIZABLE METAL, TEMPORARILY CLOSING ONE END OF THE TUBULAR SSHAPE TOEFFECTIVELY PREVENT LOSS OF REFRACTORY MATERIAL DURING THE SUSEQUENTFILLING OPERATION, FILLING THE TUBULAR GEOMETRICAL SHAPE WITH A BASICREFRACTORY MIX THROUGH AN OPEN END THEREOF, VIBRATION SAID METAL SHAPEALONG ITS LENGTH TO PARTIALLY COMPACT THE REFRACTORY MIX WITHIN THESHAPE TO A SUFFICIENT EXTENT TO CAUSE IT TO BE SELF-SUPPORTING THEREIN,PLACING THE FILLED DESIRED INTO A MOLD HOUSING SIDE AND END WALLS OF THEFINAL DESIRED FORM AND IN A SINGLE COMPRESSION STEP APPLYING PRESSURE TOTHE OUTER SURFACE OF SAID METAL SHAPE ALONG ITS LENGTH IN A DIRECTIONPERPENDICULAR TO THE DIRECTION OF VIBRATION AND FORMING THE FERACTORYFILLED GEOMETRICAL SHAPE INTO A METAL CASED REFRRACTORY BRICK HAVINGONLY ONE FABRICATION SEAM IN THE CASINGAS AND HAVING UNCEASED ENDS, SAIDBRICK BEING OF SUBSTANTIALLY THE SSAME PERMETER AS END OF A SMALLERCROSS-SECTIONAL AREA AND SMALLER VOLUME THAN THE ORIGINAL ENDS AND ATIGHTLY PACKETS BODY WITH A SMOOTH CONCESED ENDS AND A TIGHTLY PACKETSBODY WITH A SMOOTH CONTINUOUS METAL CASING INTEGRALLY ASSOCIATEDTHEREWITH.